1. Field of the Invention
This invention relates generally to a device and associated method for detecting pressures on a member, such as for measuring the pressures at a plurality of locations on a surface of a test member during wind tunnel testing, flight testing, or the like.
2. Description of Related Art
Wind tunnel testing is conventionally used for testing members such as vehicles and structures. For example, a portion of an aircraft or a full or partial model of an aircraft can be positioned in a wind tunnel and subjected to a flow of air to determine characteristics of the member. According to one typical testing method, pressures can be measured at a number of positions on the surface of the test member. For example, pressures can be detected on the wings, vertical or horizontal tail sections, or other portions of the test member. Surface pressures are also measured for full-scale flight testing of aircraft and other vehicles.
In one conventional method for monitoring generally static pressures on a test member, small pneumatic tubes are disposed throughout the test member to communicate pressure from various points of interest. For example, one end of each tube can be disposed at a surface of the test member, and the tube can extend through the test member to a scanning module. The scanning module includes a pressure sensor corresponding to each pneumatic tube, i.e., each channel of pressure measurement. Each pressure sensor provides an analog signal that is representative of the pressure in the corresponding pneumatic tube and, hence, the pressure at the corresponding point on the test member. The scanning module successively detects the pressure from each sensor, converts the analog signal to a digital signal, and multiplexes the signals for communication to another device for data recording and/or analysis.
In some cases, the number of pneumatic tubes that can be disposed on a particular test member is limited by the size of the devices. The size of each device also restricts the locations in which the devices can be provided. For example, the devices can be too large for mounting on small surfaces, in thin portions, or at sharp edges of the test member. In addition, the placement of each device requires a hole to be drilled in the test member and addition of a channel to route the pneumatic tube, thereby further limiting the number of devices that can be disposed on a single test member. Further, the size of the scanning module restricts the locations in which the scanning module can be provided. For example, conventional scanning modules typically measure more than several inches in each dimension and therefore are disposed in the test member at a location where a space of at least this size is available. Typically, the scanning module must be located remotely from some or all of the points of interest. For example, if a flap or aileron does not provide sufficient internal space for locating the scanning module, the scanning module is located remotely from the flap. The pneumatic lines must extend for some distance to the scanning module and, in some cases, the pneumatic lines must be disposed partially outside the test member, potentially interfering with the aerodynamic testing operation. For example, if the scanning module is located in a portion of the test member that is remote from a flap, pneumatic lines might extend from the module to the flap via a route that goes at least partially outside of the test member. The presence of the tubes outside of the test member can affect the measurements of the aerodynamic characteristics of the test member.
Thus, a need exists for an improved sensor device and associated method for performing such testing of a test member. The sensor device should be capable of being disposed at various locations on the test member and should provide accurate testing of the pressures at a number of locations throughout the test member.